In the new games, you can"chain fish".
You'll. need a pokemon with suction cups, and any fishing rod. Cast your line and get a bite (make sure your suction cupper is first in party) DONT MOVE FROM THE SPOT YOURE STANDING IN! Now cast again. You may either kill or run away from them.
2: hoard battle
The odds of finding a shiny in the wild is 1/8192. When you're encountering 5 at a time, it speeds it up a lot I found my first x and y shiny in a hoard. (I killed it. It was a mime jr:().
3. Friend safari.
When you add a friend code, it gives you an area to explore and catch rare pokemon in kiloude city's friend safari. The odds of finding a shiny are quite high. (Around 1/800-1000)
Masuda method-breeding with a pokemon of a different region
Soft reset- saving in front of a starter/legendary and turning your game off if the pokemon is not shiny.
Pokeradar- it's quite costly to do this one as you need 100+ repels.